Sequence control device for use in a camera system

ABSTRACT

In a camera system effective use of a single microcomputer for both automatic exposure control and automatic focus control is made possible by designing the microcomputer so that it repeats calculation for the automatic exposure control during time period for charge accumulation in a CCD focus detection sensor and during lens focusing movement and so that it performs calculation for the automatic focus control while interrupting the calculation for the automatic exposure control upon the ending of the charge accumulation in the CCD focus detection sensor and upon shifting of the lens by an amount predetermine based on the result of the calculation for the automatic focus control.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sequence control device using amicrocomputer for use in a camera system provided with automaticfocusing and automatic exposure control.

2. Description of the Prior Art

It is desired that data are processed in a high speed in parallel byusing two exclusive microcomputers for the calculation of an automaticexposure control and for the calculation of an automatic focus control.However, the cost of a camera having two microcomputers for controllinga camera becomes very expensive. Therefore, there have been proposedvarious processing ways of two above mentioned calculation using onlyone microcomputer.

For example, in the control system of a camera shown in Japanese PatentLaid Open No. 172628/1983, the calculation for exposure control isexecuted fundamentally by using interruption with a predeterminedinterval to a microcomputer for automatic focus control. However, inthis case since the calculation for the exposure control is executed byinterruption during the automatic focus control, the time period for theautomatic focus control becomes long.

In the control system of a camera shown in Japanese Patent Laid Open No.125817/1985, the time period for the automatic focus control isshortened by allowing the subsequent focus detection during thecalculation processing of the data for the automatic focus controlobtained by the preceding focus detection, but the exposure control isnot considered.

Moreover, in the control system of a camera shown in Japanese PatentLaid Open No. 172628/1983, the time period for charge accumulation in aCCD image sensor of a focus detection device varies with the brightnessof a photographic object. Additionally the driving speed of aphotographic lens for automatic focus control is different depending onthe defocus amount the shifting distance of the photographic lens to thein-focus position) or the torque necessary for shifting the photographiclens, the time interval control for the automatic focus control isdifficult, resulting in difficulty of effective use of themicrocomputer.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a sequence controldevice for use in a camera system which is able to perform the automaticfocus control and automatic exposure control with a relatively highspeed using only one microcomputor.

Another object of the present invention is to provide a sequence controldevice for use in a camera system, which is able to use onemicrocomputer effectively for both automatic focus control and automaticexposure control.

To accomplish these objects, a sequence control device according to thepresent invention is provided with a microcomputer for performingcalculation for automatic exposure control and calculation for automaticfocus control. For focus detection light receiving means of the chargeaccumulation type is used and an output signal used for the calculationfor the automatic focus control by the microcomputer and a chargeaccumulation ending signal indicating the ending of the chargeaccumulation are generated by the light receiving means. Themicrocomputer causes the light receiving means to perform the chargeaccumulation while repeating the calculation for the automatic exposurecontrol. Upon receipt of the charge accumulation ending signal from thelight receiving means at an interruption terminal, the microcomputerinterrupts the calculation for the automatic exposure control and takesin the output signal from the light receiving means so as to perform thecalculation for the automatic focus control. According to the presentinvention, since the microcomputer performs the calculation for theautomatic exposure control by making use of the time period for thecharge accumulation by the light receiving means, no time period isnecessary for the calculation of the automatic exposure control duringautomatic focus control, so that the time period for the automatic focuscontrol will not become long. Additionally, since the microcomputerperforms the calculation for the automatic focus control whileinterrupting the calculation for the automatic exposure control afterthe ending of the charge accumulation by the light receiving means,effective use of the microcomputer can be realized according to thepresent invention.

Moreover, the control device of the present invention has functions ofjudging whether a photographic lens has been shifted by a predeterminedamount based on the result of the calculation for the automatic focuscontrol, generating an interruption signal upon judgement of theshifting of the photographic lens to the predetermined position,repeating the calculation for the automatic exposure control during theshifting of the photographic lens by the predetermined amount, andstarting the calculation for the automatic focus control whileinterrupting the calculation for the automatic exposure control upongeneration of the interruption signal, whereby more effective use of themicrocomputer can be achieved according to the present invention.

The above and other objects and features of the present invention willbecome more apparent from the following description of a preferredembodiment of the present invention taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 1(A), 1(B) and 1(C) are circuit diagrams showing an embodimentof a camera system in which a data transmission device of a camera ofthe present invention is adopted,

FIG. 2 is a time chart showing an operation of the AF detection unit inFIG. 1,

FIG. 3(A) is an embodiment of serial data bus in FIG. 1,

FIG. 3(B) is an embodiment of a clock selection circuit IV in the serialI/O unit of CPU 1 in FIG. 3(A),

FIG. 4 is a circuit diagram of a decoder in a driver circuit portion inFIG. 1,

FIGS. 5 to 12 are flow charts for explaining the operation of the camerasystem in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 showing a circuit diagram of a control device of acamera system to which the present invention is applied, there isprovided a central processing unit 1 (referred to as CPU) using amicrocomputer for use in sequence control of the whole part of thecamera, calculation and control of an exposure of the camera and anautomatic focus control (referred to as AF hereinafter). CPU 1 isprovided with various kinds of input and output terminals P1 to P19, areset terminal RESET, control terminal CNTR, a serial I/O port coupledwith serial data bus SRD and AF data port coupled with an AF data busAFD.

Through the AF data bus AFD, the AF data port of CPU 1 is coupled withan automatic focus detection unit 2 (referred to as AF detection unithereinafter) for measuring a defocus value of an image of a photographicobject formed at an equivalent position equivalent to a photographicfilm surface. The AF detection unit 2 comprises a CCD image sensor (notshown) of one dimension self scan type, CCD driving unit (not shown), anA/D converter (not shown) and a standard power source (not shown) forthe A/D conversion. The CCD image sensor produces an image signal of ananalogue form upon scanning the photographic object. The image signal inan analogue form produced by the CCD image sensor is converted into adigital form and is transmitted to CPU 1 via AF data bus AFD. φAF, AFSTART and AF END are control signal lines for controlling AF detectionunit 2, which are respectively connected to the terminals P1 to P3.

Reference numeral 3 shows a display unit using liquid crystal display(LCD) elements or light emitting diode (LED) display elements, a drivingunit for the display unit and a data communication unit for receivingfrom and transmitting to CPU 1 various information such as shutter speedTv, aperture value Av which are the result of the automatic exposure(AE) calculation transmitted from CPU 1 and various photographic modes.The information mentioned above is displayed by the display unit 3 andis visually displayed in a view finder (not shown) of the camera.

Reference numeral 4 shows a lens data circuit provided in anexchangeable lens for storing various data prepared in the exchangeablelens such as minimum F number, minimum aperture value, focal length andconversion factor of a shift value of the lens necessary for a focusadjustment. When an exchangeable lens is attached to the camera, theaforementioned data are transmitted to the camera body via electricconnection terminals disposed near a portion where engaging members forengaging the exchangeable lens and the camera body are provided.

Reference numeral 5 shows a flash circuit in a flash device, whichproduces a signal representing mounting of the flash device onto thecamera body, a signal representing a guide number for indicating maximumquantity of light emitted by the flash device, a charge completionsignal representing the fact that the flash device has been charged upto be ready for flash photography and a flash light control achievementsignal representing achievement of a proper flash exposure.

Reference numeral 6 shows a light measurement unit for measuring thebrightness Bv of a photographic object. The light measurement unit 6 iscomprised of a photoelectric conversion element for receiving light fromthe photographic object and producing an analog output signalrepresenting the brightness of the object, an A/D converter forconverting the analog signal of the photo-electric conversion elementinto a digital form, a standard power source for the A/D converter and adata transfer unit which communicates with CPU 1. The light measurementunit measures the light having passed through the photographic lens ofthe camera according to the command from CPU 1.

Reference numeral 7 is a film sensitivity reader for automaticallyreading the sensitivity of a photographic film loaded in the camera. Bythe reader 7, information of the film sensitivity described on a filmcartridge containing the photographic film can be read by means ofelectric contacts provided in a cartridge chamber of the camera.

The information produced from the display unit 3, lens data circuit 4,flash circuit 5, light measurement unit 6 and film sensitivity reader 7is applied to a serial input and output port (I/O) via the serial databus SRD as the serial signals. In the serial I/O port, a suitable clockpulse of any one of predetermined clock frequencies φ₁ and φ₂ isselected corresponding to the circuits or units 3 to 7 to be used.

Reference numeral 8 is a driver controller for operating a lens drivingmotor for AF operation and various electro-magnets provided in thecamera. The driver controller 8 is controlled by control signals on thelines CMD0, CMD1, CMD2 and CMD3 coupled with the output terminals P15,P16, P17 and P18 of CPU 1. CNTR terminal is a pulse input terminal forcounting the number of pulses sent from the driver controller 8.

SW4 to SW1, SWAEL, SWMODE, SWUP and SWDN are switches, and the one endsof the switches are connected to the ground and the others arerespectively connected to the input terminals P4 to P11 via the signallines S4 to S1, AEL, MODE, UP and DN.

SW1 is a light measurement switch which is turned on when a releasebutton (not shown) of the camera is pressed down to the first stage,causing CPU 1 to generate a signal for starting the light measurementand focus detection. While the switch SW1 is on, if the lens is situatedat an out-of-focus position, the photographic lens is driven forfocusing until it arrives at an in-focus position. When the forcedepressing the release button is removed and the switch SW1 is turnedoff, the driving of the photographic lens is stopped immediately.

SW2 is a release switch which is turned on when the release button isdepressed to a second stage. In case the switch SW2 is turned on undersuch case that the shutter of the camera is releasable condition, CPU 1orders initiation of a release operation. Moreover, with the releaseswitch SW2 turned on, the light measurement switch SW1 remains on.

SW3 is a mirror up detection switch, which is turned on when a knownreflex mirror (not shown) of the camera moves to its top position forphotographing. SW4 is a switch for detecting completion of film windingby the length of one picture frame. This switch SW4 is turned off eachtime when the photographic film loaded in the camera is wound up by thelength of one picture frame, while it remains ON during wind-up of thephotographic film.

SWAEL is a switch for holding a light measurement signal generated bythe light measurement unit 6, that is, the light measurement signal isheld while the switch SWAEL is on and a new light measurement signal isapplied to CPU 1 when the switch SWAEL is turned off from the on state.SWMODE is a mode switch for selecting the exposure mode of the camera,and any one of a program mode, a diaphragm priority mode and a shutterspeed priority mode can be selected by depressing a switch SWUP or SWDNwith the mode switch SWMODE depressed simultaneously. When only theswitch SWUP or SWDN is turned on, any aperture value can be set in thediaphragm priority mode and any shutter speed can be set in the shutterspeed priority mode.

P12, P13 and P14 are output terminals, which are respectively connectedto one input terminal of each of the OR circuits OR1, OR2 and OR3 viacontrol signal lines IENDEN, RELEN and WAKEEN, and the signal linesAFEND, S2 and S1 are respectively connected to the respective otherinput terminals of the OR circuits OR1, OR2 and OR3. And the outputterminals of the OR circuits OR1, OR2 and OR3 are connected to theinterruption input terminal INT of CPU 1 via AND circuit AND1. When theterminal INT is changed to L level from H level, the CPU 1 can receivean interruption in an operative state while it starts operation in astand-by state.

RESET is a reset terminal of CPU 1 which is pulled up to +VDD by aresistor R and when the terminal RESET is changed to H level from Llevel, CPU 1 is reset. X is a crystal oscillator for applying clocksignals to CPU 1.

A focusing display unit IFD is connected to the output terminal P19. Thefocusing display unit IFD is comprised of a buzzer and an LED fordisplay (disposed in the finder of the camera) and the driving portionthereof.

The control operation of the AF detection unit 2 is explained withreference to a time chart shown in FIG. 2. CPU 1 changes the controlsignal line AFSTART to L level from H level for causing the CCD in theAF detection unit 2 to start charge accumulation (time t₀). When theamounts of charges accumulated in the CCD reaches a predetermined level,the AF detection unit 2 informs CPU 1 of the charge accumulationcompletion in the CCD by changing the control signal line AFEND to Llevel from H level (time t₁). When CPU 1 detects the L level of thecontrol signal line AFEND, the control signal line IENDEN is changed toL level from H level in order to generate interruption signal in CPU 1.Then since the control signal lines RELEN and WAKEEN are in H levelrespectively, the AND gate AND1 sends a signal which changes theinterruption terminal INT to L level from H level and the interruptionis enabled in CPU 1. And then the control signal line IENDEN isrecovered to H level from L level.

On the other hand, CPU 1 changes the control signal line AFSTART to Hlevel (time t₂) by detecting L level of the control signal line AFEND,and when the AF detection unit 2 detects the H level on the lineAFSTART, the control signal line AFEND is returned to H level (time t₃)and the image information represented by the accumulated charges fromthe CCD which are converted into digital form is read into CPU 1. Whenthe focus detection of the AF detection unit 2 is finished and thetiming for enabling the shutter release comes, the control signal lineRELEN is changed to L level from H level. Then since both of the controlsignal lines IENDEN and WAKEEN are H level, the terminal INT is changedto L level from H level and an interruption occurs again in CPU 1, andthen the control signal line RELEN is returned to H level from L level.

FIG. 3(A) shows an embodiment of serial data bus for communication amongthe display unit 3, lens data circuit 4, flash circuit 5, lightmeasurement unit 6, film sensitivity reader 7 and CPU 1. FIG. 3(B) showsan embodiment of a clock selection circuit in the serial I/O unit ofCPU 1. I is a serial clock generator for producing serial clock pulses,II is a chip select signal generator for generating chip select signalsCSLM, CSDSP, CSDX, CSLENS and CSFLASH which are chip select signals forselecting light measurement unit 6, display unit 3, film sensitivityreading unit 7, lens data circuit 4 and flash circuit 5 respectively,and III is a data communication unit for communicating serial data onthe basis of the output pulse SCK from the clock selection circuit IV.As shown in FIG. 3(B) each signal of CSLM, CSDSP and CSDX are applied toan AND gate AND2 and the output signal thereof is applied to one of theinputs of an AND gate AND3. Each signal of CSLENS and CSFLASH is appliedto one of the inputs of AND gates AND4 and AND5 respectively and is alsoapplied to another input of the AND gates AND5 and AND4 respectively viainverters INV1 and INV2. The output signals of the AND gates AND4 andAND5 are applied to an OR gate OR4 the output signal of which is appliedto another input of the AND gate AND3. The output signal of the AND gateAND3 is applied to one of the inputs of an AND gate AND6 and is alsoapplied to one of the inputs of an AND gate AND7 via an inverter INV3.Clock pulse of frequency φ₁ and clock pulse of frequency φ₂ which islower than the frequency φ₁ are applied to respective inputs of the ANDgates AND7 and AND6. The output signals of the AND gates AND6 and AND7are applied to the OR gate OR5 and are transmitted as a serial clocksignal SCK from the OR gate OR5.

Table 1 shows a logic table in the block diagram as mentioned above.

                  TABLE 1                                                         ______________________________________                                        CSLM  CSDSP    CSDX    CSLENS CSFLASH AND3  SCK                               ______________________________________                                        L     H        H       H      H       L     φ.sub.1                       H     L        H       H      H       L     φ.sub.1                       H     H        L       H      H       L     φ.sub.1                       H     H        H       L      H       H     φ.sub.2                       H     H        H       H      L       H     φ.sub.2                       ______________________________________                                    

In Table 1, in case, for example, the light measurement unit 6 isselected, only CSLM signal becomes L level and the other signals becomeH level, and in this case an L level signal is output from the AND gateAND3, then the AND gate AND7 is enabled and the serial clock pulses SCKof clock frequency φ₁ are generated from the OR gate OR5. As shown inTable 1, when any one of the light measurement unit 6, display unit 3 orfilm sensitivity reading unit 7 is selected, the clock frequency of theserial clock pulses SCK becomes φ₁ and when the lens data circuit 4 orflash circuit 5 is selected, the frequency of the serial clock pulsesSCK becomes φ₂ which is slower than φ₁.

Since the lens and flash device are connected to the camera body via theelectric contacts, the delay of the signal transmission is apt to beproduced and the serial data may not be communicated correctly.Therefore the smaller clock frequency φ₂ is adopted as a frequency ofthe serial clock signal SCK upon communication of the CPU 1 with lensdata circuit 4 and the flash circuit 5.

Next, the driver controller 8 and other controllers are explained.

1CMG is an electro-magnet for holding the leading shutter curtain, andwhen the control output line 1CMGO becomes L level, the magnet 1CMG isenergized to hold the leading shutter curtain. 2CMG is an electro-magnetfor holding the trailing shutter curtain, and when the control outputline 2CMGO becomes L level, the magnet 2CMG is energized to hold thetrailing shutter curtain. The interval between timing of release of theleading shutter curtain and the timing of release of the trailingshutter curtain corresponds to the shutter speed. FMG is a diaphragmarresting electro-magnet which arrests the diaphragm in a predeterminedposition when the control output line FMGO is kept at L level for apredetermined interval.

Reference numerals Q₁ to Q₆ are transistors. The transistors Q₁ to Q₄are for driving a photographing sequence motor M₁ and connected in abridge shape so that the sequence motor M₁ can be driven in a reversiblemanner. The transistors Q₃ to Q₆ are for driving a lens driving motor M₂and connected in a bridge shape so that the lens driving motor M₂ can bedriven in a reversible manner. Both terminals of the sequence motor M₁are connected to the common connecting point of the transistors Q₁ andQ₂ and to the common connecting point of the transistors Q₃ and Q₄, andalso both terminals of the lens driving motor M₂ are connected betweenthe common connecting point of the transistors Q₃, Q₄ and the commonconnecting point of the transistors Q₅, Q₆. It is noted that thetransistors Q₃ and Q₄ are used in common in said two bridge circuits.The sequence motor M₁ is a photographing sequence control motor, which,upon forward rotation, causes a mirror drive mechanism (not shown) tolift up the reflex mirror to its top position and a diaphragm operatinglever (not shown) to stop down the diaphragm, while upon reverserotation, winds up the photographic film and restores the mirror drivemechanism and the diaphragm operating lever to their initial state, sothat the reflex mirror is returned to its lower inclined position and sothat the diaphragm is returned to its fully open position. The lensdriving motor M₂ is a motor for driving a lens used for the AFoperation, which upon forward rotation, shifts the lens forward and uponreverse rotation, shifts the lens rearward. OM₁ to OM₆ are controlsignal lines for switching each of the transistors Q₁ to Q₆.

Table 2 shows the on and off condition of the transistors Q₁ to Q₆controlled by the control signal lines OM₁ to OM₆ respectively in orderto control the sequence motor M₁ and lens driving motor M₂.

                  TABLE 2                                                         ______________________________________                                        Q1   Q2      Q3     Q4   Q5    Q6   M1      M2                                ______________________________________                                        OFF  OFF     OFF    OFP  OFF   OFF  Stop    Stop                              ON   OFF     OFF    ON   OFF   OFF  Forward Stop                              OFF  ON      ON     OFF  OFF   OFF  Reverse Stop                              ON   OFF     ON     OFF  OFF   OFF  Brake   Stop                              OFF  OFF     OFF    ON   ON    OFF  Stop    Forward                           OFF  OFF     ON     OFF  OFF   ON   Stop    Reverse                           OFF  OFF     ON     OFF  ON    OFF  Stop    Brake                             ______________________________________                                    

In the above mentioned embodiment, the six transistors Q₁ to Q₆ are usedwith tWo transistors Q₃ and Q₄ used for both of the bridge circuits, sothat the two motors M₁ and M₂ are prevented from simultaneous driving.By this arrangement, the number of the terminals of CPU 1 and the drivercontroller 8 can be reduced, and the size of the driver 8 in a substratecan be reduced.

Reference numerals 81 and 82 denote respectively a diaphragm encoder andAF encoder each composed a photocoupler. The diaphragm encoder and AFencoder are connected to the driver controller 8 via the control signallines PD₁, PT₁ and PD₂, PT₂ respectively.

The diaphragm encoder 81 is arranged to monitor the stroke of thediaphragm operating lever during the stopdown operation of the diaphragmin the course of a camera releasing operation. The control signal linePD₁ becomes H level during the camera releasing in response toenergization of the diaphragm arresting electro-magnet FMG and the lightemitted by the light emitting diode 81a is detected by the phototransistor 81b and the signal produced by the photo transistor 81b isapplied to the driver controller 8 via the control signal line PT₁. Theoutput signal of the photo transistor is wave shaped into pulse by thedriver controller 8 and is sent to the the count input terminal CNTR ofCPU 1 via the control signal line CNTRO. The control signal line PD₁ iskept in L level except for a period of the camera releasing.

AF encoder 82 is arranged for monitoring the revolutions of the lensdriving motor M₂, that is, the amount of movement of the lens at thetime of AF operation. At the time of AF operation, the control signalline PD₂ becomes H level and the light emitted by the light emittingdiode 82a is detected by the photo transistor 82b and the output signalof the photo transistor 82b is applied to the driver controller 8 viathe control signal line PT₂. Then the signal is sent to the terminalCNTR of CPU 1 via the control signal line CNTRO after the signal iswaveshaped into pulse by the driver controller 8. The aforementionedcontrol signal line PD₂ is in L level except at the time of the AFoperation.

In the present embodiment as mentioned above, both the signals from thediaphragm encoder 81 and AF encoder 82 are applied to the terminal CNTRof CPU 1 after being waveshaped by the driver controller 8. Thus, thenumber of the terminals of the driver controller 8 and CPU 1 can bereduced.

CMD0 to CMD3 are control signal lines from the output terminals P15 toP18 of CPU 1 for control of the driver controller 8.

The arrangement of the decoder unit in the driver controller 8 isexplained with reference to FIG. 4.

Each of the control signal lines CMD0 to CMD3 forms the lines 1, 3, 5and 7 of the matrix structure, and the control signal lines CMD0 to CMD3are inverted by inverters INV11 to INV14 so as to form the lines 2, 4, 6and 8. Then the lines 1 and 4 are connected to an AND gate AND11 and thelines 2, 3, 6 and 7 are connected to an AND gate AND12. AND gates AND13to AND25 are respectively connected to the lines as shown in FIG. 4. Theoutput terminals of the AND gates AND11 and AND12 are connected to an ORgate OR11 and the output of the OR gate OR11 is connected to a driveramplifier AMP. The output of the driver amplifier AMP becomes the signalline OM₁ and other control signal lines OM₂ to OM₆, 1CMGO, 2CMGO, FMGO,PD₁ and PD₂ are respectively formed by tbe arrangement of invertersINV15 to INV18, OR gates OR12 to OR16, AND gate AND26 as shown in FIG.4.

Table 3 shows the logic values of the outputs of the decoder and therespective operation of the camera.

    TABLE 3      Control order of CPU Output of driver circuit  CMD0 CMD1 CMD2 CMD3 OM1     OM2 OM3 OM4 OM5 OM6 1CMGO 2CMGO FMGO PD1 PD2 Control operation of     camera   H H H H L H L H L H H H H L L Camera stop  H H H L L H L L H H     H H H L H Motor M.sub.2 forward rotates (forward lens     shift), count AF pulse  H H L H L H H H L L H H H L H Motor M.sub.2     reverse rotates (rearward lens                shift), count AF pulse  H     H L L L H H H H H H H H L L Motor M.sub.2 brake  H L H H H H L L L H L L     H H L Motor M.sub.1 (mirror up), leading and                trailing     shutter curtains hold,                count diaphragm pulse  H L H L H H     L L L H L L L L L Motor M.sub.1 (mirror up), leading and     trailing shutter curtains hold,                diaphragm MG on  H L L H     H H L L L H L L H L L Motor M.sub.1 (mirror up), leading and        trailing shutter curtains hold  H L L L H H H H L H L L H L L Motor     M.sub.1 brake, leading and                trailing shutter curtains hold      L H H H L H L H L H H L H L L trailing shutter curtain hold  L H H L L     L H H L H H H H L L Motor M.sub.1 (wind)  L H L H H H H H L H H H H L L     Motor M.sub.1 (brake)

By this arrangement, six control signal lines OM₁ to OM₆ for driving themotors M₁ and M₂, three control signal lines 1CMGO, 2CMGO and FMGO forcontrolling three magnets 1CMG, 2CMG and FMG, and two control signallines PD₁ and PD₂ for controlling the two light emitting diodes 81a and82a, thus, total eleven control signal lines can be controlled by thesignals from four control signal lines CMD0 to CMD3, and therefore thenumber of the output terminals of CPU 1 and the circuit lines can bereduced.

The operation of the camera system according to the arrangementmentioned above is explained with reference to flow charts shown inFIGS. 5 to 12 hereinafter.

First, when a battery is mounted in a camera body and the power issupplied to the reset terminal RESET of CPU 1 via the resistor R, theterminal RESET is set to H level from L level, whereby CPU 1 is resetand the battery loading routine is executed as shown in FIG. 5.

In the step #1 the port of I/O portion in CPU 1, the memory portion RAM(random access memory) and flags for judging various kinds of conditionsare cleared and the program goes to the stand-by routine. In the step #2the flags are initialized, and in the step #3 timers accommodated in CPU1 are stopped and interruptions by the timers are inhibited. In the step#4 a starting interruption is permitted. Thus, the control signal lineWAKEEN is changed to L level from H level so that the startinginterruption by turn-on of the light measurement switch SW1 can bepermitted when the release button is depressed to the first stage. Inthe step #5 CPU 1 stops the clock and goe to the stand-by condition.

In the stand-by condition of CPU 1, the control signal lines IENDEN andRELEN are set to H level and only the control signal line WAKEEN is in Llevel as mentioned above. Therefore, each output of the OR gates OR1 andOR2 is settled in H level in spite of the condition of the controlsignal lines AFEND and S2 applied to the other inputs of the OR gatesOR1 and OR2. In case the release button is not pressed and the lightmeasurement switch SW1 is off, the control signal line S1 which isapplied to the other input of the OR gate OR3 is set to H level and theOR gate OR3 generates H level, therefore H level is applied to theinterruption terminal INT via the AND gate AND1.

Next, when the light measurement switch SW1 is turned on from off statewhen the release button is depressed to the first stage, the controlsignal line S1 becomes L level and the OR gate OR3 generates L level,and therefore the output of the AND gate AND1 is changed to L level fromH level. Thus the starting interruption takes place and CPU 1 is changedto starting condition from stand-by condition, and the starting routineas shown in FIGS. 6(A) to 6(C) is executed.

In the step #10 the condition of the starting flag is judged. Thestarting flag is set to "1" after the starting of CPU 1 and is reset to"0" immediately before CPU 1 becomes to be in the stand-by condition.Therefore, immediately after the starting of CPU 1, the starting flag is"0" and the program goes to the starting process program of the step#11. In the step #11 the aforementioned starting flag is set "1" and thecontrol signal line WAKEEN is changed to H level from L level. Thus, theOR gate OR3 generates H level, whereby the interruption terminal INT iskept in H level via the AND gate AND1, preventing the startinginterruption from occurring in CPU 1 again. In the step #12 the CCD inAF detection unit 2 is initialized and unnecessary charges stored in theCCD when the camera is not used are removed. In the step #13, CPU 1waits for a period of time ΔT₁ to initialize the CCD, and then theinitialization of the CCD is finished in the step #14. Subsequently theprogram goes to the light measurement process beginning from the step#15.

In the step #15 a command signal for starting the light measurement istransmitted from the serial I/O portion to the light measurement unit 6via the serial data bus SRD, whereby the measurement of the brightnessof a photographic object through the lens is started. In the next step#16 the timer TMR2 for holding the power source is set and started. Incase the switches SW1, SW2, SWAEL, SWUP and SWDN are not closed till thetime interval ΔT₅ set in the timer TRM2 passes, CPU 1 enters thestand-by condition. In the step #17 the state of the light measurementswitch SW1 is judged, and in case the switch SW1 is off, i.e., thecontrol signal line S1 is in H level, the program goes to the loop fromthe step 17 to the light measurement routine of the step #20.

The light measurement (LM) routine is explained with reference to FIG.7. In the step #200 the state of each of the switches SWMODE, SWUP, SWDNis read, whereby the exposure mode as well as the aperture value Av andthe shutter speed Tv in each exposure mode is set. In the step #201 thefilm sensitivity Sv read by the film sensitivity reading unit 7 istransmitted to CPU 1 via the serial data bus SRD. In the step #202 thesignal representing the mounting of the flash device onto the camera,the charge completion signal and the flash control achievement signal,etc. are transmitted to CPU 1 from the flash circuit 5 via the serialdata bus SRD. In the step #203 the lens data such as the minimum Fnumber, the minimum aperture value, the focal length and the conversionfactor of the mounted exchangeable lens are transmitted to CPU 1 fromthe lens data circuit 4 via the serial data bus SRD. As described above,the frequency of the clock signal on the serial data bus SRD is selectedto be φ₁ or φ₂ depending on whether the destination of the datacommunication with the CPU 1 is the circuits 3, 6 and 7 in the camerabody or the circuits 4 and 5 connected to the outside via the electriccontacts.

In the step #205 the condition of the focusing zone flag is judged. Theflag is set to "1" by the focus detection when the lens is in an infocuscondition or when it is brought into an in-focus condition after thelens is driven by the AF operation. And only when the lens is not in anin-focus condition i.e. the flag is set to "0", the brightness value Bvof a photographic object is measured again by the light measurement unit6 in the step #206. This is because there is a function in the presentembodiment that the brightness value Bv is kept unchanged once when thelens is set to an in-focus position.

In the step #210 the aperture value Av and the shutter speed Tv arecalculated according to a predetermined algorithm using the data read inthe above steps #200 to #206. In the step #211 the calculated data aswell as the set exposure mode data is transmitted to the display unit 3via the serial data bus SRD in order to have the display unit displaythe calculated aperture value Av, shutter speed Tv and exposure mode inthe finder. In the step #212 the data such as aperture value Av and filmsensitivity Sv are transmitted to the flash circuit 5. Since a series ofthe operation with reference to the exposure calculation is finishedwhen the above mentioned steps #200 to #212 are completed, the AFpriority flag is set to "1" in the next step #213. The AF priority flagis set for determining which of the light measurement loop and the datatake in operation from the CCD is to be performed primarily duringcharge accumulation in the CCD when the light measurement routine isperformed.

In the step #214 the condition of a consecutive or continuousphotographing delay flag is judged. In case the consecutivephotographing delay flag is reset to "0", the program goes to the step#218 but in case of "1" of the consecutive photographing delay flag, theprogram goes to the step #215, as described below. The steps #215 to#217 constitutes a loop for judging whether the consecutivephotographing delay is to be interrupted or not.

In the step #215 the state of the release switch SW2 is judged, and incase the release switch SW2 is on, the program goes to the step #218 andthe consecutive photographing delay mode is kept. but in case the switchSW2 is off, the consecutive photographing delay mode is interrupted.That is, the consecutive photographing delay flag is reset to "0" in thestep #216, and in the next step #217 a timer TMR4 is stopped and aninterruption by the timer TMR4 is inhibited. Thus, the consecutivephotographing delay mode is interrupted when the release switch SW2 isturned off during operation of the consecutive photographing, andtherefore, consecutive photographing of higher speed becomes possible byturning the release switch SW2 on again.

In the next step #218 the states of the various kinds of operationswitches SW1, SW2, SWAEL, SWMODE, SWUP and SWDN are detected forjudgement of whether or not the power source is to be further suppliedto the control device and the time interval ΔT₅ is set again by thetimer TMR2 for holding power source in the step #219 only when any oneof the switches is closed. After that, the program returns to the step#17 of the starting routine in the step #220.

When none of the switches SW1, SW2, SWAEL, SWMODE, SWUP and SWDN isclosed and the time interval ΔT₅ passes after the timer TMR2 for holdingthe power source is started, a timer interruption by the timer TMR2takes place as shown in FIG. 8.

In this case, a stack pointer is reset in the step #250 and the programjumps to the step #2 in the step #251, whereby subsequently CPU 1 entersin the stand-by condition.

On the other hand, in case the "on" state of the light measurementswitch SW1 is detected in the step #17, the program goes to theintegration (charge accumulation) routine beginning from the step #21.

In the step #21 the control signal for the AF detection unit 2 on theline AFSTART is changed to L level from H level, whereby the commandsignal for starting the charge accumulation at the CCD is sent out andthe charge accumulation in the CCD is started. In the next step #22, acharge accumulation finishing interruption is enabled. That is, thecontrol signal line IENDEN of CPU 1 is changed from H level to L levelso that the CPU 1 can receive an external interruption when the amountsof the charges stored in the CCD reach a predetermined level and thecontrol signal line AFEND is changed from H level to L level indicatingthe finishing of the charge accumulation in the CCD. In the next step#26 the state of the light measurement switch SW1 is judged, and in casethe switch SW1 is on, the program returns to the loop of the steps #26to #27 again of the light measurement routine in the step #27 as shownin FIG. 7 and waits for the charge accumulation finishing interruption.

In case the camera is once brought into the operating condition from thestand-by condition by turn on of the light measurement switch SW1, andthen the light measurement and the charge accumulation in the CCD aresimultaneously started, the program goes through the light measurementroutine in the step #27 at least one time but the image information datafrom the CCD is not received when the AF priority flag is not set to "1"in the step #213.

On the other hand, when it is judged in the step #26 that the lightmeasurement switch SW1 is off, the control signal line AFSTART from theoutput terminal P2 of CPU 1 is recovered to H level from L level in thestep #26, whereby the command signal to compulsively stop the chargeaccumulation in the CCD is transmitted to the AF detection unit 2. Andin the step #30 the control signal line IENDEN is recovered to H levelfrom L level, whereby the charge accumulation finishing interruption isdisabled and subsequently the program returns back to the step #17.

In case the charge accumulation in the CCD is finished and the controlsignal line AFEND is changed from H level to L level while the programis going round the loop of the steps #26 to #27, the charge accumulationfinishing interruption takes place as described above and the programgoes to the steps after the step #10.

Thus, the program goes to other routine by interrupting CPU 1 when thecharge accumulation in the CCD is finished because the time interval forthe charge accumulation in the CCD varies with the brightness of thephotographic object and the time interval control of the routine for thecharge accumulation becomes difficult, so that CPU 1 cannot be utilizedeffectively.

In the step #10 the condition of the starting flag is judged, but theprogram goes to the step #40 from #10 because CPU 1 has been alreadystarted and the starting flag has been set to "1", whereby the CPU 1judges whether or not take-in of the image information from the CCD viathe AF data bus is being effected and in case the take-in operation isfinished, the program goes to the release process routine after the step#60 after an interruption is disabled in the step #41. In case the imageinformation is being taken at this time, the program goes to the routineof the charge accumulation finishing interruption process beginning fromthe step #42.

In the step #42 it is judged whether or not the AF priority flag hasbeen set, and in case the program has not gone round the lightmeasurement routine at all and the AF priority flag has not been set to"1", the priority is given not to the take-in operation of the imageinformation from the CCD but to the light measurement. To this end,after the command signal for starting charge accumulation is transmittedagain to the AF detection unit 2 in the steps #48 and #49 as in thesteps #21 and #22 mentioned above, the charge accumulation finishinginterruption is enabled. In the next step #50 the program goes back tothe steps #26 and #27 of the former routine.

On the other hand, in case the AF priority flag has been set to "1" inthe step #42, the program goes to the step #43 wherein it is judgedwhether or not the consecutive photographing delay flag has been set "1"by termination of wind-up of the photographic film. In case theconsecutive photographing delay flag has been set to "1" during thedelay in the consecutive photographing, the program goes to the step #48without taking the image information from the CCD, so that chargeaccumulation in the CCD is effected again. On the other hand, in casethe consecutive photographing delay flag has been reset to "0", theprogram goes to the step #44 and the image information from the CCDconverted into the digital form in the AF detection unit 2 istransmitted in turn to CPU 1 via the AF data bus AFD. The AF priorityflag is reset "0" in the step #45, and the stack pointer is reset forpreventing the program from returning to the former routine in the step#46. Hence, in the step #47 the program jumps to the AF process routinebeginning from the step #100 as shown in FIGS. 9(A) and 9(B).

Thus, charge accumulation in the CCD is started in the step #21 at thesame time of the starting of the light measurement calculation in thestep #15, but even if the charge accumulation in the CCD is finishedduring the first light measurement calculation with the AF priority flagset to "0", the charge accumulation in the CCD is only repeated throughthe steps #42 to #48 without taking the image information from the CCD.Therefore, the charge accumulation in the CCD may be finished in acomparatively short time by getting out of the loop of the steps #26 and#27 from the time of the end of the light measurement calculation, andthe program can go to the AF process routine. Hence, the process timeinterval can be shortened as compared with a case where the chargeaccumulation in the CCD is started after the end of the first lightmeasurement calculation. That is, in case the photographic object iscomparatively dark and it takes a long time for the charge accumulationin the CCD, the charge accumulation is finished after the end of thelight measurement calculation and, therefore the time interval requiredfor judging the focus condition becomes shorter than in the case wherethe charge accumulation is started after the end of the lightmeasurement calculation.

In case the photographic object is comparatively bright and short timeis necessary for the charge accumulation in the CCD, the chargeaccumulation is finished in a period during the light measurementcalculation. However, as the charge accumulation in the CCD is startedagain, the time interval from the end of the light measurementcalculation to the end of the charge accumulation in the CCD, atmaximum, becomes equal to the time interval required when the chargeaccumulation is started after the end of the light measurementcalculation and this time interval is generally half of the timeinterval necessary for the charge accumulation in the CCD in average.

The reason why the image information from the CCD is not taken in butcharge accumulation in the CCD is started again in the step #43 to #48even if the interruption by finishing of the charge accumulation in theCCD takes place with the consecutive photographing delay flag is set to"1" is as follows:

If the image information from the CCD is taken in response to the chargeaccumulation finishing interruption occurred in the period of theconsecutive photographing, the amount of defocusing, that is the amountof the shifting of the photographic lens for the AF operation, iscalculated, and in case it is judged that an in-focus condition has beenalready achieved (the amount of defocusing is zero), the lens is held atthe in-focus position. As a result, in case a photographic object movesor the field of view is changed in the consecutive photographing beforethe camera release is enabled, the focus point may be shifted upon thecamera release effected after cancellation of the consecutivephotographing mode.

Accordingly, the image information from the CCD is taken-in after thecanceling of the consecutive photographing mode, whereby the amount ofdefocusing of the AF operation is calculated.

AF process routine is shown in FIG. 9. The amount and the direction ofdefocusing are calculated by processing the image information receivedfrom the CCD in AF detection unit 2 via AF data bus AFD in the step#100. The focus condition of the lens is judged in the step #101. Incase the defocus amount is beyond a predetermined value, it is judged asa defocus condition and the program goes to the AF motor control routinebeginning from the step #112. In case the defocusing amount is below theaforementioned predetermined value, it is judged as an in-focuscondition and the program goes to the in-focus process routine beginningfrom the step #102.

In the step #102, the in-focus display is executed by a buzzer providedin the in-focus display unit IFD in FIG. 1 or a light emitting diode LEDin the finder. In the next step #103 the in-focus zone flag is set "1"in order to memorize the in-focus condition. In the step #104 the signalcontrol line RELEN connected to the output terminal P13 is changed fromH level to L level in order to permit a release interruption by therelease switch SW2. When the release switch SW2 is turned on, theinterruption takes place and the program goes to the release processroutine after the #60 as shown in FIG. 6.

Subsequently, with the photographic lens held in the in-focus condition,the condition of the light measurement switch SW1 is judged in the step#105, and in case the switch SW1 is on, after executing the lightmeasurement routine again in the step #106, the program rounds the loopreturning to the step #105 and wait for the interruption by the releaseswitch SW2. On the other hand, in case the light measurement switch SW1is off, the program goes to the step #107 from the step #105 and thein-focus display is turned off, and after the in-focus zone flag isreset to "0" in the step #108, the program jumps to the step #17 in FIG.6 after the step #107.

Next, AF motor control routine after the step #112 is explained.

First, the defocus amount calculated in the step #100 is converted to apulse train having the number N₁ on the basis of the lens shiftingconversion factor read from the lens in the step #112. Theaforementioned pulse number N₁ is compared with a predeterminedreference pulse number N₀ in the steps #113 and #114, and in case of N₁≧N₀ it is judged that the defocus amount is comparatively large and theprogram goes to the FAR zone process routine beginning from the step#140, while in case of N₁ <N₀ it is judged that the defocus amount iscomparatively small and the program goes to the NEAR zone processroutine beginning from the step #115.

In the step #140 a pulse counter in CPU 1 is started after the value ofN₁ -N₀ is set in the counter. In the step #141, the AFMF flag formemorizing that the AF motor M₂ is driven in FAR zone is set "1". In thestep #142 an interruption by the counter is enabled, and in the step#143 the AF motor M₂ is driven continuously to shift the photographiclens in a high speed toward the in-focus position on the basis of thedefocus direction calculated in the step #100. Then the control signallines CMD0 to CMD3 from CPU 1 to the driver controller 8 are changed toH, H, H, L levels or H, H, L, H levels, respectively, depending on thedefocus direction. After the AF priority flag is reset to "0" in thestep #144, the program goes round the loop of the judgement of thecondition of the light measurement switch SW1 and the light measurementroutine formed by the steps #145 and #146. This loop is different fromthe loop of the aforementioned steps #105 and #106 since the programwaits for a counter interruption by the end of the AF drive of the lensby the AF motor M₂. When the photographic lens is shifted by the AFmotor M₂ and the predetermined number N₁ -N₀ of the pulse train fed fromthe AF encoder 82 to the CNTR terminal of CPU 1 is counted by the pulsecounter, the counter interruption takes place and the program goes tothe pulse counter interruption routine after the step #150 shown in FIG.10.

CPU 1 judges at the step #150 whether the camera is effecting the camerareleasing operation or AF operation. In case the AFMF flag or AFMN flaghas been set to "1", it is judged that the camera is effecting the AFoperation, and the program goes to an AF motor pulse interruptionroutine beginning from the step #160. In this case since thephotographic lens is in the FAR zone, the program goes to the step #171from the step #160 and AFMF flag is reset to "0" in the step #171. Inthe step #172 the reference pulse number N₀ is set in the pulse counter,and in the step #173 the counter is started, while in the step #174 thecounter interruption is enabled. In the step #175 the stack pointer isreset, which is necessary for returning from the counter interruptionroutine to the former routine. Accordingly, the program does not go backto the former routine from the interruption process routine but jumps tothe next routine, whereby in the step #176 the program jumps to the NEARzone control routine beginning from the step #121.

Going back to the step #114 in FIG. 9, in case of N₁ <N₀, it is judgedthat the defocus amount is comparatively small, then the program goes tothe NEAR zone process routine after the step #116. This routine isdifferent from the FAR zone process routine after the step #140. Thatis, the AF motor M₂ is driven at a low speed by intermittent pulses inorder to prevent the lens from overrunning the destination to be stoppedand the light measurement routine is not called at all. This is partlybecause the defocus amount is small and partly because the lens canreach the in-focus position is a short time and further partly becausethe process in CPU 1 can be simplified.

After the pulse number N₁ is set in the pulse counter in the step #116,the counter is started in the step #117. The counter interruption isenabled in the step #118 and the AFMN flag for memorizing the NEAR zonedrive is set to "1" in the step #121. In the next step #122 the AF motorM₂ is driven but after waiting for a predetermined time interval AT10 inthe step #123, the AF motor M₂ is turned off in the step #124 and issimultaneously applied with the brake in the step #125. In the step#126, the brake of the lens driving motor M₂ is released after thepredetermined time interval ΔT₁₁. Then in the step #128 the state of thelight measurement switch SW1 is judged, and in case of on state, theprogram goes back to the step #122 and continues to round the loop ofthe steps #122 to #128.

During the above mentioned process the number of the pulses generatedfrom the AF encoder 82 by the intermittent driving of the lens drivingmotor M₂ is counted by the pulse counter, and when the count valuebecomes N₁, a counter interruption takes place in CPU 1 and the programgoes to the pulse counter interruption routine as shown in FIG. 10.

Thus, the loop of the steps #122 to #128 and in the loop of the steps#145 to #146 are interrupted when the shift of the lens by the lensdriving motor M₂ is finished and the program goes to the other step.This is necessary because the time interval necessary for shifting thelens is changed in dependence upo the defocus amount and the lenstorque, so that the time interval control of the driving routine of thelens driving motor M₂ becomes difficult, resulting in difficulty ineffective use of CPU 1.

In this case the AFMN flag has been set, and therefore the program goesto the step #150→#160 →#161 in FIG. 10 and the lens driving motor M₂ isstopped. In the next step #163 the AFMN flag is reset to "0". In thestep #164 the lens driving motor M₂ is braked and after waiting for apredetermined time interval Δ₇ in the step #165 the lens driving motorM₂ is released from the brake in the step #166. In the step #167 thestack pointer is reset and in the step #168 the program jumps to thestep #21 in FIG. 6 to start charge accumulation in the CCD and goesround the light measurement routine of the step #27 again. At this time,since the AF priority flag has been reset to "0", the operation mode ofthe camera is turned to the light measurement priority mode and afterthe program goes round the light measurement loop one time. CPU 1 isallowed to take-in the image information from CCD. This is because thelight measurement calculation is omitted in the NEAR zone controlroutine in FIG. 9.

In the AF process routine in FIG. 9, in case the light measurementswitch SW1 is turned off during the driving of the lens driving motorM₂, the program goes to the step #130 from the step #128 or the step#145 and the lens driving motor M₂ is stopped, and in the step #131 thecounter interruption is inhibited. In the step #132 both of AFMF andAFMN flags memorizing that the lens driving motor M₂ is in driving, arereset to "0" and in the step #133 the program jumps to the step #17 inFIG. 6 and goes to the light measurement or AF routine.

Going back to FIG. 9, in case the release switch SW2 is turned on, afterthe lens is set in the in-focus position by the AF operation, therelease interruption takes place since the release interruption isenabled in the step #104, and the program goes back to the startingroutine in FIG. 6, wherein the steps #10, #40, #41 are executed in orderand the program goes to the release process routine.

First in the step #41 interruptions other than the counter interruptionare disabled and in the step #60 the focusing zone flag set in the AFroutine is reset to "0", and in the step #61 the command of stopping thelight measurement is transmitted to the light measurement unit 6 via theserial data bus SRD. In the next steps #62 and #63 the control signallines CMD0 to CMD3 are respectively changed to H, L, H and L levels forthe driver controller 8, thereby the electro-magnets 1CMG an 2CMG of theleading shutter curtain and trailing shutter curtain are held andthereafter the mirror up command is transmitted to the driver controllerso that the sequence motor M₁ is rotated forward to cause the mirrordrive mechanism to lift up the reflex mirror. In the step #64 theaperture value Av calculated in the exposure calculation routine isconverted to the aperture diaphragm step number according to the minimumF number of the attached lens, and in the step #65 the converted valueis set in the pulse counter in CPU 1. In the step #66 the counterinterruption is enabled. In the step #67 the state of the switch SW3 fordetecting the mirror-up is judged and the program stays in the step #67till the switch SW3 is turned on by finishing the mirror-up. During thisprocess the pulse generated from the diaphragm encoder 81 is beingapplied to the CNTR terminal of CPU 1 from the driver controller 8, andwhen the number of pulses counted by a counter in the CPU 1 becomesequal to the corresponding value of the diaphragm step number set in thestep #65, the counter interruption takes place and the program proceedsto the counter interruption process routine beginning from the step #150shown in FIG. 10.

In the step #150 it is judged which of the camera release operation andAF operation is now performed. In this case since the camera releaseoperation is performed, the diaphragm interruption process programbeginning from the step #151 is executed. In the step #151 the counterinterruption is disabled, and in the step #152 the control signal linesCMD0˜CMD3 to the driver controller 8 are respectively changed to H, L, Hand L levels, whereby the electro-magnet FMG for arresting the diaphragmis energized and the diaphragm operating lever is arrested to set thediaphragm aperture. After waiting for the time period ΔT₆ in the step#153, the control signal lines CMD0˜CMD3 are respectively changed to H,L, L and H levels, whereby the electro-magnet FMG for arresting thediaphragm operating lever is de-energized in the step #154.Subsequently, the program goes back to the step #67 of the camerarelease process rouline in FIG. 6 in response to a return commandproduced in the step #155.

In the step #67 when the switch SW3 is turned on by finishing of themirror-up, the program goes to the step #69 and the control signal linesCMD0 to CMD3 are respectively changed to H, L, L, L levels, thereby thebrake for the sequence motor M₁ is turned on. After waiting for the timeperiod ΔT₄ in the step #70, the control signal lines CMD0 to CMD3 arerespectively changed to L, H, H and H levels, whereby the brake for thesequence motor M₁ is turned off. Furthermore, in the step #72 theelectro-magnet 1CMG is de-energized, whereby the leading shutter curtainis released and starts moving. In the step #74 when the time periodcorresponding to the shutter speed Tv calculated in the exposurecalculation routine has lapsed from the releasing of the leading shuttercurtain, the control signal lines CMD0 to CMD3 are respectively changedto H, H, H and H levels in the step #75, whereby the the electro-magnet2CMG is de-energized and the leading shutter curtain is released tomove. Thus the shutter is opened for the time period corresponding tothe shutter speed Tv. After finishing the release process program in thesteps #60 to #75, the stack pointer is reset in the step #76, and in thestep #77 the program jumps to the step #80 of the film winding processroutine in FIG. 11.

In the step #80 the control signal lines CMD0 to CMD3 to the drivercontroller 8 are respectively changed to L, H, H and L levels, wherebythe sequence motor M₁ is driven in reverse direction for the winding upthe film. When in the step #81 the switch SW4 for detecting the filmwinding is turned off by finishing the film winding by the length of onepicture frame, the program goes to the step #83 and the control signallines CMD0 to CMD3 are respectively changed to L, H, L and H levels,whereby the sequence motor M₁ is braked. After waiting for the timeperiod ΔT₈ in the step #84, the control signal lines CMD0 to CMD3 arerespectively changed to H, H, H and H levels, whereby the brake for thesequence motor M₁ is turned off in the step #85. In the step #86 thestate of the release switch SW2 is judged, and in case of "off" of theswitch SW2, the program jumps to the step #15 of the light measurementprocess routine shown in FIG. 6 in the step #90, but in case of still"on" of the switch SW2, the program goes to the camera release operationand the next photographing is executed immediately when the lightmeasurement and focus detection are finished.

In the present embodiment, the camera release operation is inhibited forthe predetermined time period ΔT₉ from the time of finishing the filmwinding operation (see the step #85) even if the light measurement andfocus detection have been finished, whereby the consecutivephotographing which is against the intention of the camera operator canbe prevented.

That is, the consecutive photographing delay flag is set to "1" in thestep #87. This flag is used for judging whether the camera releaseoperation has been enabled in the light measurement routine afterfinishing the film winding. In the next step #88, a timer TMR4 is setthe time period ΔT₉ and started. In the step #89 the interruption whichtakes place after ΔT₉ from the time of the starting of the timer TMR4 isenabled. Then the program goes to the light measurement process routineof the step #15 in the step #90. When the interruption of the timer TMR4takes place in the light measurement loop after the finishing of thefilm winding by the length of one picture frame, the timer interruptionroutine of the consecutive photographing beginning from the step #280shown in FIG. 12 is executed.

The timer TMR4 is stopped in the step #280, and the aforementionedconsecutive photographing delay flag is reset to "0", and the programreturns to the first routine in the step #282.

Thus, in case the release switch SW2 is kept in the on state after thefinishing of the film winding, the subsequent camera release is startedafter the period of ΔT₉, so that any of the single photographing mode orthe consecutive photographing mode can be selected in accordance withthe operator's will.

As described above, in case the destination of the data communication ofCPU 1 is a circuit inside the camera body, the clock frequency φ₁ of theserial data is selected, so that the data is transmitted in a highspeed. On the other hand, in case the destination of the datacommunication of CPU 1 is a circuit connected to the camera via theelectrical contacts, the clock frequency φ₂ slower than the clockfrequency φ₁ is selected, so that the correct data can be transmitted byslowing the transmission speed.

In the aforementioned embodiment, though the clock frequency of theserial data is changed depending on whether the destination of the datacommunication of CPU 1 is a circuit inside or outside the camera body,this may be modified according to the kind of the process whether thedestination circuit arrangement is formed by bipolar transistors or CMOStransistors or according to whether the controller of the destination isa hardware or software, or by a suitable combination of theseconditions.

What is claimed is:
 1. A control device for use in a camera system forautomatic exposure control and automatic focus control, comprising:amicrocomputer for performing calculation for the automatic exposurecontrol and calculation for the automatic focus control; and lightreceiving means of the charge accumulation type for accumulatingelectrical charges in response to light incident thereon to generate anoutput signal used for the calculation for the automatic focus controlby the microcomputer, and wherein the microcomputer has a function ofcausing the light receiving means to perform the charge accumulation inparallel with the calculation for the automatic exposure control and,upon the ending of the charge accumulation, operates either in a firstmode in which it causes the light receiving means to perform the chargeaccumulation without taking in the output signal from the lightreceiving means while continuing the calculation for the automaticexposure control or in a second mode in which it takes in the outputsignal from the light receiving means so as to start the calculation forthe automatic focus control.
 2. The control device according to claim 1,further comprising means for causing the microcomputer to start itsoperation in response to a manual operation, wherein the microcomputeroperates in the first mode during the time period from the start of theoperation of the microcomputer till the end of the first timecalculation for the automatic exposure control after the start of theoperation of the microcomputer.
 3. The control device according to claim1, further comprising means for shifting a photographic lens of thecamera system to an in-focus position in accordance with the result ofthe calculation for the automatic focus control, wherein themicrocomputer operates in the first mode during the time period fromarrival of the photographic lens at the in-focus position till the endof the first time calculation for the automatic exposure control afterthe arrival of the photographic lens at the in-focus position.
 4. Acontrol device for use in a camera system for automatic exposure controland automatic focus control, comprising:a microcomputer for performingcalculation for the automatic exposure control and calculation for theautomatic focus control, the microcomputer having an interruptionterminal for accepting an interruption; and light receiving means of thecharge accumulation type for accumulating electrical charges in responseto light incident thereon to generate an output signal used for thecalculation for the automatic focus control by the microcomputer, thelight receiving means is also capable of generating a chargeaccumulation ending signal indicating the ending of the chargeaccumulation therein; and wherein the microcomputer has a function ofcausing the light receiving means to perform the charge accumulationwhile repeating the calculation for the automatic exposure control and,upon receipt of the charge accumulation ending signal at theinterruption terminal, takes in the output signal from the lightreceiving means to perform the calculation for the automatic focuscontrol while interrupting the calculation for the automatic exposurecontrol.
 5. A control device for use in a camera system for automaticexposure control and automatic focus control, comprising:a microcomputerfor performing calculation for the automatic exposure control andcalculation for the automatic focus control; and lens shifting means forshifting a photographic lens of the camera system based on the result ofthe calculation for the automatic focus control; wherein themicrocomputer has functions of judging whether the photographic lens hasbeen shifted by an amount predetermined based on the result of thecalculation for the automatic focus control, generating an interruptionsignal upon judgement of the shifting of the photographic lens by thepredetermined amount, repeating the calculation for the automaticexposure control during the shifting of the photographic lens by thelens shifting means and starting the calculation for the automatic focuscontrol while interrupting the calculation for the automatic exposurecontrol upon generation of the interruption signal.